Heart Failure Flashcards
give 8 causes of HF
- ischaemic heart disease (most common
- HTN
- valvular heart disease
- AF
- chronic lung disease
- cardiomyopathy
- previous cancer chemo drugs
- HIV
what are the 2 broad categories of HF
- HFrEF: less than 50%
- HFpEF: greater than 50%, diastolic dysfunction where there is an issue with the LV filling with blood during diastole
ejection fraction: % of blood in the LV squeezed out with each ventricular contraction
what are the key symptoms of HF
- Breathlessness, worsened by exertion
- Cough, which may produce frothy white/pink sputum
- Orthopnoea, which is breathlessness when lying flat, relieved by sitting or standing (ask how many pillows they use)
- PND
- Peripheral oedema
- Fatigue
what signs may you find O/E of a patient with HF
- Tachycardia
- Tachypnoea
- Hypertension
- Murmurs on auscultation indicating valvular heart disease
- 3rd heart sound on auscultation
- Bilateral basal crackles (sounding “wet”) indicating pulmonary oedema
- Raised JVP
- Peripheral oedema of the ankles, legs and sacrum
what are 3 possible mechanisms of PND
- fluid settles across large SA of lungs as pt lies flat to sleep causing dyspnoea. as they stand up, the fluid sinks back to the lung cases and upper lung areas can function more effectively
- resp centre in brain becomes less responsive during sleep so RR and effort do not inc in response to dec o2 sats - develops more significant p.congestion and hypoxia
- dec adrenaline circulating during sleep = more relaxed myocardium = dec CO
what is BNP
hormone released from the heart ventricles when the myocardium is stretched beyond the normal range
- raised BNP blood result indicates the heart is overloaded beyond its normal capacity to pump effectively
what is the action of BNP (2)
- relaxes smooth muscle in blood vessels which reduces systemic vascular resistance making it easier for blood to pump through the system
- acts on kidneys as a diuretic to promote water excretion in the urine which reduces the circulating volume, helping to improve the function of the heart in someone that is fluid-overloaded
describe the specificity/sensitivity of BNP
sensitive but not specific meaning when it is negative it rules out HF but can be positive due to other reasons e.g:
- tachycardia
- sepsis
- PE
- renal impairment
- COPD
what are appropriate blood tests to investigate HF and explain their use
- U&Es: baseline renal function and diuretic effect
- FBC: anaemia as consequence of bone marrow issue
- LFTs: hepatic congestion
- TFT: thyroid disease
- ferritin/transferrin: younger pt w HH
- BNP
what are appropriate radiological investigations into HF and explain their use
- CXR
- ECHO/MRI: assess LV function and structural abnormalities
what are CXR findings of HF
what causes upper lobe diversion in HF
- usually when standing erect, lower lobe veins contain more blood and upper lobe veins remain small
- in acute LVF, there is back-pressure such that the upper lobe veins fill with blood and become engorged - upper lobe diversion
- this is visible as increased prominence and diameter of the upper lobe vessels on CXR
what additional x-ray findings does fluid leaking from oedeamtous lung tissue in HF cause
- bilateral pleural effusions
- fluid in interlobar fissures
- fluid in septal lines - Kerley B lines
what are possible findings on echo of LV in HF
- dilated poorly contracting LV (systolic dysfunction)
- stiff, poorly relaxing, small diameter LV (diastolic dysfunction)
- valvular heart diseasea
- atrial myxoma
- pericardial disease
what is the use of cardiac MRI in assessment of HF
- may elaborate cause for HF as the echo may miss the RV
- scar estimation + coronary disease assessment for viability of cardiac muscle
what is pulmonary oedema and how does it arise
lung tissue and alveoli are filled with interstitial fluid which interferes with normal gas exchange causing SOB and reduced O2 sats
how is the severity of symptoms related to HF graded
New York Heart Association
* Class I: No limitation on activity
* Class II: Comfortable at rest but symptomatic with ordinary activities
* Class III: Comfortable at rest but symptomatic with any activity
* Class IV: Symptomatic at rest
what is the conservative management of HF
- smoking cessation
- restriction of alcohol consumption
- salt restriction
- fluid restriction esp in presence of hypoN + daily weight monitoring
what is the management of acute LV failure
SODIUM
- Sit up: helps to oxygenate lungs as gravity takes fluid to lung bases
- Oxygen: use ABG to guide therapy
- Diuretics: inc output of kidneys, reduces volume of fluid in circulation allowing heart to pump blood more effectively
- IV fluids should be stopped
- Underlying causes need to be identified and treated (e.g., myocardial infarction)
- Monitor fluid balance
what are appropriate medications to prescribe in HF
- diuretics 1st line
- ACEi
- ARB
- ARNI
- B-blockers
- hydralazine/isosorbide mononitrate
- ivabradine
- nitrates
how are diuretics used to manage HF
furosemide 40-500mg daily in divided doses
- may be given IV esp when pt fluid overloaded
- larger doses may be needed in renal impairment
- prolonged infusions i.e. 250mg over several hours has better effect
- bumetanide may be better absorbed orally and have advantages when pt is oedematous
- thiazides + loop
urine input and output monitoring as well as daily weighing to assess response to treatment
what is a consequence of long-term diuretic use and how is this corrected
potassium depletion
- counterbalance with ACEi
- if hypoK persists then spironolactone 25mg OD
what is the use of ACEi in HF
improve symptoms and signs of all grades of HF even if the pt is asymptomatic
- improves exercise tolerance
- slows disease progression
- improves survival
when can angiotensin receptor-neprilysin inhibitors be used in HF
sacubitril
symptomatic chronic heart failure with reduced ejection fraction, only in people:
- with class II to IV symptoms
- left ventricular ejection fraction of 35% or less
- already taking a stable dose of ACEI or ARBs
how is ivabradine beneficial in HF
in patients who either cannot tolerate β-blockers, or in whom the resting heart rate is higher than 75 despite β-blockers
- pt must be in sinus rhythm to benefit
- avoid with diltiazem or verapamil
- does not affect BP!
what is the action of nitrates (3)
- reduce preload
- reduce pulmonary oedema
- reduce ventricular size
how are nitrates beneficial in HF
when there is underlying ischaemia, HTN or regurgitant aortic/mitral valve disease
- in chronic heart failure, useful for relief of orthopnoea and exertional dyspnoea
- caution with aortic/mitral stenosis, HOCM and pericardial constriction
what are the surgical options of management of HF where medical management has failed
- ICD: continually monitor heart and apply defibrillator shock to cardiovert pt back into sinus IF shockable arrhythmia (used in pt who previously had v.tach or v.fib
- CRT: may be used in severe HFrEF <35%. CRT involves biventricular (triple chamber) pacemakers, with leads in the right atrium, right ventricle and left ventricle - objective is to synchronise the contractions in these chambers to optimise heart function
what are the 3 core symptoms of cardiac tamponade
Beck’s Triad
- hypotension
- raised jugulat pressure
- muffled heart sounds
what is pulsus paradoxus
a sign caused by cardiac tamponade which leads to an abnormally large drop in BP during inspiration causing a disappearing radial pulse on inspiration
